The advent of genomic sciences has led to a new concept of drug discovery. Genomics-derived drugs from the new concept consist of DNA-related drugs, protein drugs and small molecule drugs that react with a target gene or protein. Some of these therapeutic agents have been promoted to the human clinical stage. However, it is not easy to obtain efficacy through a conventional delivery technologics. A delivery system, aka “vector”, is necessary for efficient delivery of the DNA-related drugs such as genes, antisense compounds and ribozymes. In addition, new delivery systems are required for the practical use of therapeutic protein drugs. New delivery systems will be necessary for other genomics-derived compounds such as peptides. As indicated above, new delivery systems will certainly play an important role in the future development of the new drugs. This review will summarize the importance and contribution of DDS to genornics-based medicine.